Commit b586627e authored May 06, 2019 by Dan Carpenter Committed by Daniel Thompson May 12, 2019

kdb: do a sanity check on the cpu in kdb_per_cpu()



The "whichcpu" comes from argv[3].  The cpu_online() macro looks up the
cpu in a bitmap of online cpus, but if the value is too high then it
could read beyond the end of the bitmap and possibly Oops.

Fixes: 5d5314d6 ("kdb: core for kgdb back end (1 of 2)")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

parent ecebc5ce

kernel/debug/kdb/kdb_main.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2583,7 +2583,7 @@ static int kdb_per_cpu(int argc, const char **argv)
		diag = kdbgetularg(argv[3], &whichcpu);
		if (diag)
		return diag;
		if (!cpu_online(whichcpu)) {
		if (whichcpu >= nr_cpu_ids \|\| !cpu_online(whichcpu)) {
		kdb_printf("cpu %ld is not online\n", whichcpu);
		return KDB_BADCPUNUM;
		}

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